1. Field of the Invention
The present invention pertains to the art of pools and, more particularly, to heating and circulating systems for pools.
2. Discussion of the Prior Art
Community and backyard swimming pools have become a common part of recreation and exercise activities. In order to expand the usable season for swimming pools, it has become somewhat commonplace to utilize auxiliary heaters in combination with conventional circulation systems.
In FIG. 1 a typical, known pool heating and circulating system is generally illustrated at 2. In such an arrangement, an electric motor 5 that receives power through an electrical line 7 is used to drive a pump 10 through a transmission member 12. Pump 10 is connected to a suction line 15 that stems, at least in part, from a skimmer 17 in order to draw water from a swimming cavity 18. Water flowing from pump 10 is delivered through an output line 20 to a filter 23 where the water is purified such as through sand filtration or the like. From the filter 23, the water passes to a return line 27 and is delivered back to the swimming cavity 18 through a plurality of nozzle outlets 30-33.
If it is desired to also heat the water, an electric heater 35 is generally placed in series with and downstream of the filter 23. The heater 35 would be periodically activated to maintain the water in swimming cavity 18 at a desired temperature based on the sensed temperature of the water. A typical electric heater 35 is generally illustrated in FIG. 2. As its main components, heater 35 includes a condenser 39, an evaporator 41, an expansion valve 43 and a compressor 46 arranged in series, as well as a fan unit 49. In general, such a heater 35 functions to transfer heat from the air surrounding the unit to the water. This is performed by transforming a liquid refrigerant placed in the evaporator 41 into a gas by drawing in warm air by means of fan unit 49. The gas flows through the compressor 46 wherein the gas is compressed to a much higher temperature. This heated gas then enters the condenser 39 wherein it is placed in heat exchange relationship with the pool water which causes the water to be heated and the gas to be condensed to a liquid. This process continues as long as heater 35 remains on.
There are various drawbacks associated with such known pool heating and circulating systems. First of all, the electric motor 5 and the heater 35 are essentially two independent components, even though they can work in unison, and require separate power lines. Even though each of these units may be considered rather energy efficient, together they can be quite costly to operate. In addition, this type of heater 35 can really only function with moderate ambient temperature changes since it relies on the heat available in the air to heat the water.
There are also other types of heating systems that are available including, for example, passive heating systems, electrical resistance heating units and propane heating arrangements. All of these additional heating arrangements also suffer from various drawbacks. For instance, the passive heating systems are completely dependent upon the sun and are greatly affected by numerous variables including cloud coverage; electrical resistance heating units can boost the temperature of the pool water rather quickly but are rather costly to operate; and propane heating arrangements are simple not widespread due to the need to have a separate source of propane fuel and since they are only slightly more efficient than electrical resistance heating units.
Therefore, there exists a need in this art for a more efficient heating and circulating system that can be used in a wide range of climates and, in addition, a pool heating and circulating system that is compact so that it occupies a minimal of space.